When rekeying a cylinder using a traditional cylinder design, the user is required to remove the cylinder plug from the cylinder body and replace the appropriate pins so that a new key can be used to unlock the cylinder. This typically requires the user to remove the cylinder mechanism from the lockset and then disassemble the cylinder to some degree to remove the plug and replace the pins. This requires a working knowledge of the lockset and cylinder mechanism and is usually only performed by locksmiths or trained professionals. Additionally, the process usually employs special tools and requires the user to have access to pinning kits to interchange pins and replace components that can get lost or damaged in the rekeying process. Finally, professionals using appropriate tools can easily pick traditional cylinders.
In addition, in one form of a master keying system, such as a pin and tumbler design, master shims are positioned in between the pins of the lock cylinder to establish a shear line for the master key and user keys. In such a previous design, for example, the consumer replaces the pins and adds shims to convert the lock cylinder to a master keyed cylinder. This may be a complicated process for some consumers.
The present invention overcomes these and other disadvantages of conventional lock cylinders and master keying systems.